ASP.NET "AutoPostBack" Sample

After publishing our ASP.NET Flex Table Sample last week, I was surprised that the part of the code which I received the most questions on was that the form posted back to the server automatically whenever the value of the drop down list was changed. I wish I could take credit for it... but it's a really simple feature built into ASP.NET called AutoPostBack.

AutoPostBack is built into the form-based server controls, and when enabled, automatically posts the page back to the server whenever the value of the control in question is changed. Because of the additional server requests it causes, it's not something you'll want to enable for all your controls, but for things that affect page display or change choices further down the form, it can be really handy. Not to mention the fact that it will save you a lot of time and headaches over trying to implement something similar on your own. Not that it's really all that complex to do on your own if you're good with javascript, but it's hard to get any simpler then just setting AutoPostBack="True"

Here's a zip file of the code (1 KB).

Play with the running version.

View the live source code.